The present invention relates to a method for preventing the passage of a mining vehicle, preferably an unmanned mining vehicle, the method comprising the defining of an accepted operating range for a mining vehicle provided with a power unit of its own and steered by means of wireless data transfer or an independent navigation system incorporated in the vehicle and controlling that the vehicle stays within the accepted operating range by stopping the vehicle if it tries to leave the operating range.
The present invention further relates to an arrangement for preventing the passage of a mining vehicle, preferably an unmanned mining vehicle, the arrangement comprising a mining vehicle provided with a power unit of its own, the mining vehicle being steered within a predetermined operating range by means of wireless data transfer or an independent navigation system incorporated in the vehicle.
Automated and other unmanned mining vehicles, such as vehicles steered from a distant control room on the ground, have been designed for excavation and mining industry with the aim of improving both the safety and working conditions of the staff and to improve productivity. An aspect that must always be taken into account in connection with the use of automated equipment is safety. It is an issue that has to be addressed also when remote-controlled equipment is concerned, because the site of operation is not directly visible to the operator. Legislation on safety at work requires the use of safety arrangements when such equipment is used. Even if a site of operation is normally unmanned, every now and then there are persons and other vehicles, manned and unmanned, moving in the vicinity. In case a vehicle should break away from the area reserved for it, due to an operational disturbance for example, a serious risk of collision might occur. In prior art solutions the accepted operating range of unmanned mining vehicles is defined by using for example photocells and mechanical gates provided with limit switches. This is a fairly simple arrangement for an electrically driven vehicle to which the driving power is supplied over a supply cable from outside the operating range of the vehicle. If the vehicle for some reason tries to leave the accepted area, the photocells or gates detect this and the power supply from the supply cable is switched off. Consequently, the vehicle stops and cannot cause a safety hazard. This system functions well and reliably for mining vehicles, the power supply of which being controllable from the outside of the operating range. The situation is different for independent diesel- and battery-driven mining vehicles and those running on any other independent power source, because they have no fixed connection to the outside of the operating range. Instead, the control data needed for steering and controlling the equipment is transmitted as wireless data transfer from the control site to the vehicle. It is also possible that the vehicle is provided with an independent navigation system, which does not necessarily require any outside control during operation. In either case, it is impossible to arrange an emergency stop based on wireless data transfer alone because in the demanding conditions concerned, disturbances may occur in the radio connection.
It is an object of the present invention to provide a method and an arrangement that allows the safety of unmanned mining vehicles to be improved.
The method of the present invention is characterized in that the accepted operating range is defined using at least one horizontal barrier boom arranged at the operating site, above the highest point of the mining vehicle; that the mining vehicle is provided with a mast extending to said barrier boom; and in that when the mining vehicle is at the barrier boom, the mast hits the boom, thereby triggering an emergency stop switch arranged in connection with the mast to stop the mining vehicle.
The arrangement of the present invention is further characterized in that the arrangement comprises a mast arranged at the mining vehicle, the mast being provided to extend above other portions of the vehicle, and in that in connection with the mast there is provided an emergency stop switch which is provided to stop the mining vehicle when the mast hits a horizontal barrier boom defining the accepted operating range of the mining vehicle and arranged within the reach of the mast.
An essential idea of the present invention is that horizontal barrier booms are arranged at a suitable height at the upper part of a mine gallery or a similar operating site to determine an accepted travel range for an unmanned mining vehicle provided with a power unit of its own. The mining vehicle, in turn, is provided with a mast which is higher than other portions of the vehicle, so if the mining vehicle for some reason tries to leave the accepted area, the mast hits the boom, thereby triggering an emergency stop switch arranged in connection with the mast to stop the vehicle. This prevents the vehicle from leaving the predetermined area. Further, an essential idea of a preferred embodiment of the present invention is that movable barrier booms are arranged in mine galleries, the booms being pivotable in a transverse direction with respect to the mine gallery or to the side of it, thereby allowing the accepted travel range of the unmanned vehicle to be conveniently defined.
An advantage of the present invention is that it is now possible to essentially improve the operational safety of unmanned mining vehicles provided with a power unit of their own, such as diesel- or battery-driven vehicles, and to reliably control any exceptional circumstances. A vehicle that strays away from the accepted area causes a mechanical contact between the barrier boom and the emergency stop switch, whereby the movement of the vehicle is stopped before more serious damage is caused. The emergency stop operates mechanically; therefore any disturbances occurring in wireless data transfer as well as other unreliability factors are avoided. The arrangement of the present invention is also simple and economical to manufacture. Moreover, its structure is reliable and substantially maintenance free.